JPH0537523Y2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Field of Application] This invention relates to a waveguide bandpass filter intended to suppress unnecessary frequencies in radar equipment and the like.

[Prior Art] Conventionally, a high-power waveguide bandpass filter used in radar equipment, etc., has unit main waveguides 1, 2, and 3 connected to flanges 1 at both ends, as shown in FIG.
A, 1B, 2A, 2B, 3A, 3B are connected to each other, and rod-shaped reactance elements 4, 5, 6 are inserted into each main unit waveguide 1 to 3 by penetrating its wide surface.
and fix it by soldering, and then attach flanges 1B and 2.
Spacer 8 between A and flanges 2B and 3A,
By increasing or decreasing the number of spacers 8 and 9 inserted, the VSWR characteristics and frequency of the passband can be adjusted.

[Problems that the invention aims to solve] However, in this structure, when the number of stages of reactance elements increases, the number of flanges increases, processing costs increase, and the weight also increases. . Further, when airtightness is required, there is a problem in that it is difficult to maintain airtightness with a structure that requires a spacer. Furthermore, even if the total length of the main waveguide is determined by considering the dimensions of the spacer and the flange and spacer are omitted, there may actually be processing errors in the reactance element or machining of the reactance element mounting position of the main waveguide. Due to errors,
With such an unadjusted structure, there was a problem in that it was extremely difficult to satisfy the VSWR characteristic specifications.

An object of the present invention is to provide a waveguide bandpass filter whose frequency and VSWR can be easily adjusted.

[Means for Solving the Problems] The configuration of the present invention for achieving the above object will be explained with reference to FIGS. 1 to 3 corresponding to the embodiments. In a waveguide bandpass filter in which reactance elements 4 to 7 are arranged in multiple stages at predetermined intervals in the longitudinal direction of the main waveguide 10 in a direction transverse to the wide surface of the main waveguide 10, the longitudinal direction of the main waveguide 10 is Openings 14 to 16 are provided in the narrow surface of the main waveguide 10 corresponding to areas where the magnetic field distributions 11 to 13 are strong between the reactance elements 4 and 5, 5 and 6, and 6 and 7 adjacent to each other. ,
One end side of sub-waveguides 17-19 is connected to the external narrow surface of the main waveguide 10 using the openings 14-16 as communication ports, and a short plate is connected to the other end side of the sub-waveguides 17-19. 20 to 22 are provided.

[Function] In this way, the frequency and VSWR can be easily adjusted by adjusting the positions of the shot plates 20 to 22 with respect to the sub waveguides 17 to 19.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings. 1 and 2 show a first embodiment of the present invention. This example shows the case where the resonance mode is TE ₁₀₁ . As shown in the figure, the waveguide bandpass filter of this embodiment has a rectangular main waveguide 10, and flanges 10A and 10B are attached to both ends thereof. Inside the main waveguide 10, rod-shaped reactance elements 4, 5, 6, and 7 are passed through the main waveguide 10 in multiple stages at predetermined intervals in the longitudinal direction in a direction transverse to the wide surface of the main waveguide 10, and are fixed by soldering. ing. Between the reactance elements 4 and 5 adjacent in the longitudinal direction of the main waveguide 10, 5,
Openings 14, 15, 16 are provided alternately on both narrow sides of the main waveguide 10, corresponding to the areas where the magnetic field distributions 11, 12, 13 between 6 and 6 and 7 are strong. These openings 14 to 16 are used as communication holes, and auxiliary waveguides 17 and 1 are provided on the external narrow surface of the main waveguide 10.
8 and 19 are connected to each other. A short plate 20 is provided at the other end of each sub waveguide 17 to 19,
21 and 22 are slidably fitted together.

According to the waveguide bandpass filter having such a structure, the adjacent reactance elements 4 and 5
The short plates 20 to 20 of each sub-waveguide 17 to 19 make electrical subtle adjustments to the intervals between
This can be done by changing the position of 22. That is, the VSWR, attenuation characteristics, etc. of this bandpass filter can be easily adjusted by moving the shot plates 20 to 22 while looking at the display on a display such as a cathode ray tube. Short plate 20-2
2, each short plate 20 to 22 is fixed to the sub waveguides 17 to 19 by soldering. This soldering allows for sufficient airtightness.

In this embodiment, a three-stage direct connection type was described, but the number of stages may be any number, and the reactance element may be of an iris type. Further, although the sub-waveguide is shown as having the same size as the main waveguide, it may be larger or smaller. Furthermore, although the short plate is shown as a block type, it may also be of a York type.

FIG. 3 shows a second embodiment of the present invention. This example shows a case where the resonance mode is TE ₁₀₂ (TE ₁₀₁ is shown in the middle).
Note that the resonance mode is also valid for TE _10o (n is a natural number).

[Effects of the invention] As explained above, the waveguide type bandpass filter according to the invention can be improved by changing the position of the short plate of the sub-waveguide having the short plate.
Since the VSWR and attenuation characteristics were adjusted,
It has the advantage that it is easy to make adjustments to obtain good VSWR characteristics, and it is also easy to make fine adjustments to the passband region and attenuation region.

[Brief explanation of the drawing]

1 and 2 are longitudinal cross-sectional views and perspective views showing a first embodiment of a waveguide bandpass filter according to the present invention, and FIG. 3 is a longitudinal cross-sectional view showing a second embodiment of the present invention. FIG. 4 is a perspective view of a conventional waveguide bandpass filter. 4-7... Reactance element, 10... Main waveguide, 11-13... Magnetic field distribution, 14-16... Opening, 17-19... Sub-waveguide, 20-22...
Short board.

Claims (1)

[Scope of utility model registration request] In a waveguide bandpass filter in which reactance elements are disposed in multiple stages at predetermined intervals in a main waveguide in a direction that crosses a wide surface of the main waveguide, the reactance elements are arranged in a plurality of stages at predetermined intervals in the main waveguide in the longitudinal direction of the main waveguide. An opening is provided on the narrow surface of the main waveguide corresponding to a place where the magnetic field distribution between the reactance elements is strong, and a sub-waveguide is provided on the narrow surface outside the main waveguide using the opening as a communication port. A waveguide-type bandpass filter characterized in that one end of the sub-waveguide is connected to the sub-waveguide, and a short plate is provided on the other end of the sub-waveguide.